The elect king rejected a type of the Lord Jesus

The elect king is now rejected. He repairs to the priest, who
gives him the hallowed bread, according to the sovereign grace of
God, who rises above the ordinances that are connected with
blessing, when that blessing is rejected -- when He Himself is
rejected in His chosen one, and in the power of His testimony. When
this is the case, He sets faith above ordinances in His sovereign
grace. Since God Himself and His testimony are rejected, the
shewbread was considered common. God in fact was ordering all
anew.

It was precisely the case of the Lord Jesus. The Person of the
rejected One is above all the carnal ordinances, which have lost
their signification where He is. Christ submitted indeed to all the
ordinances and authorities; but the rejection of God's testimony in
Him caused it to be perceived by degrees that He was One greater
than the ordinances -- One who set them aside, and replaced them by
the manifestation of the effectual and eternal grace of God. It was
much more important to give David food than to keep that which had
grown old. God cared more for him than for the bread of the
tabernacle.

The sword of Goliath in a new arsenal

David then takes the sword of Goliath. It was by the power of
death that the Lord destroyed all his strength who had the power of
death. Death is the best weapon in the arsenal of God, when it is
wielded by the power of life.

Refuge sought among the Philistines but driven forth by God

David, his mind full of Saul's enmity, seeks refuge among the
Philistines. What business had he there? This time God drives him
thence without chastisement, but abundantly proving to him at the
same time that he was out of place there. We escape from the wisdom
which leads us into the midst of God's enemies, by the shame of that
folly which causes us to be driven out again.